There were 276 drowning deaths in 2018-19, a 10 per cent increase from the previous financial year.

Over the three summer months alone there were 123 drowning deaths, a 17 per cent increase compared to the 10-year average.

Royal Life Saving Society Australia and Surf Life Saving Australia have launched their own safety reports together at Parliament House on Monday.

They warn risky behaviour around waterways and poor swimming ability continue to impact drowning rates.

"Last summer was particularly bad on our waterways," Royal Life Saving chief executive Justin Scarr said.

Hotter, drier weather would lead to more people in the water and it is important Australians practise water safety, he said.

"Unfortunately, more people in the water means more people at risk of drowning," he said.

Swimmers have been advised to supervise their kids, to stick between the flags and learn lifesaving skills.

There were 122 coastal drowning deaths in 2018-19, marking a 14 per cent increase from 2017-18.

Nearly 90 per cent of the people who drowned at the coast were male, with alcohol and drugs a big factor, Mr Scarr said.

Coastal drownings combines the number of drownings at beaches, rock or cliff locations and offshore.

The majority, or 58 per cent, of coastal drowning deaths occurred at the beach.

Rivers accounted for the majority of all drowning deaths, with 80 deaths representing 29 per cent of all drowning fatalities in 2018-19.

People aged 20-24 make up the highest number of coastal drowning victims, with nearly half of all coastal drownings - 42 per cent - happening during summer.

Over half of drowning deaths of kids aged under four occurred in swimming pools, but drownings in that age bracket decreased by 30 per cent against the 10-year average.

NSW recorded the highest number of drowning deaths, followed by Queensland.

The ACT recorded the lowest rate, with only two deaths in 2018-19.

Victoria was the only state to record an increase in drowning deaths against the 10-year average.

Australian Associated Press